This invention relates to a hollow mill tool and more particularly to a mill tool which is adapted to mill the outside diameter of a cylindrical work piece with repeat cuts of the inserts within a tolerance of 0.001 inch.
Cutting inserts for milling tools are mounted in a variety of ways. Typical arrangements for mounting an insert on the tool holder pockets include the use of V-bottom inserts, top clamps, and adjustable mounts. The use of V-bottom inserts quickly wear out the tool holder pockets. Top clamps are positioned between tool posts to clamp the inserts against it""s tool post and, by being so positioned, tend to cause chip clearance problems. Adjustable cutter mounts are difficult to align precisely on the cutting diameter and they tend to stray from their adjusted positions during cutting operations.
This invention provides a hollow milling tool having a cylindrical shank portion and a plurality of radially spaced and axially extending tool posts integrally formed with and projecting from the shank portion about a longitudinal axis of the tool. Each tool post is provided with a cutting insert mounting face and each mounting face defines a first plurality of axially extending serrations. A cutting insert is mounted on each mounting face and each cutting insert is provided with a second plurality of axially extending serrations which define a back face of the insert. The insert serrations mesh with the serrations of the mounting face. A threaded fastener extends through a front face of each cutting insert and is threadedly received in each of the tool posts to securely hold each cutting insert against it""s tool post.
Each tool post has a mounting pocket for it""s cutting insert and clear radial spacing is provided between the tool posts for effective chip removal during a cutting operation.
A cutting insert may be provided on the shank and within the cutting circle of the milling tool to permit cutting and/or chamfering of an end of the workpiece.
The tool posts may be spaced unequally about the cutting circle to minimize harmonic vibrations at higher cutting speeds.